Fluid distribution systems, for e.g. heating, cooling and water supply are designed to feed a fluid from a source to a consumption point. Each consumption point typically has a calculated and designed flow or differential pressure requirement. However depending on the type of hydronic system, the flow requirement is often variable over time and can change with factors like seasonality (e.g. summer or winter), that changes the load from the consumption points, temperature changes of the system fluid, changes in consumption of the system fluid (e.g. for drinking water).
Control valves (e.g. sliding stem valves, rotary valves, etc.) are frequently used in fluid distribution system and have a variable opening such that the flow rates can be controlled. It is commonly known to provide an actuator (e.g. electric or pneumatic) in association with a control valve in order to provide for automatic operation of the control valve. In their most basic form, actuators are provided with manual means of operation, often in the form of a handwheel which allows local operators to manually adjust the flow rate. However, most conventional actuators are provided with a set of jumpers or dipswitches in order to control and to configure operating parameters of the actuator.
These actuators are rather limited in their operational control, and it is often a very cumbersome task for a local operator to manage sites where there are large amounts of actuators. Some valve actuators are able to connect to a larger grid having a control desk or a common node from which the plurality of valve actuators may be controlled. However, oftentimes there still needs to be a local operator in case of various failures or during setup of HVAC (heating, ventilation and air conditioning) systems.
As mentioned conventional systems only provide a limited number of options for the different parameters that need to be adjusted. This limits the flexibility of operation of the actuators and consequently limits the performance in various applications that the actuators are used with.
Moreover, another drawback of currently known systems is during the installation or setup of an HVAC system, i.e. before there is a possibility to connect the actuators to the power or control grid.
To this end the local operators are forced to mechanically/manually (by e.g. using a hand wheel) operate the valve actuators in these situations e.g. to adjust the stroke of the actuator. This quickly becomes an overwhelming task for even the most skilled operators, especially when dealing with large numbers of control valves and even more so if the local operator needs to configure all of the actuators according to some predefined operating parameters.
There is therefore a need for an improved method and system for operating valve actuators, in particular when the valve actuators are disconnected from a power grid or control grid.